TB1 Problems :(

[Alexbaker443]

Hello,

I bought the TB1 mic today. I'm running it into a DMX 6Fire soundcard. The problem is I'm getting a low hum the whole time (too bad to ignore). The high end noise/signal ratio is fine, but there's a low done/hum (around about a G). If I turn the gain up to ampplfiy what is also a quiet signal, it amplifies the low noise too. This is my first tube mic. Do you think it's faulty? I can't see that it's supposed to be like this, considering it gets good reviews.
Thanks for any feedback,
Alex
x

[hargerst]

Sometimes, the top shell does not make a solid contact with the bottom shell and that ungrounded part can cause a hum such as you describe. Try tightening the screws that hold the top on and see if that fixes it. It's a common problem with a lot of big condenser mics.

[Alan Hyatt]

Hello,

I bought the TB1 mic today. I'm running it into a DMX 6Fire soundcard. The problem is I'm getting a low hum the whole time (too bad to ignore). The high end noise/signal ratio is fine, but there's a low done/hum (around about a G). If I turn the gain up to ampplfiy what is also a quiet signal, it amplifies the low noise too. This is my first tube mic. Do you think it's faulty? I can't see that it's supposed to be like this, considering it gets good reviews.
Thanks for any feedback,
Alex
x

Alex,

I e-mailed you earlier, but again, there could be grounding issues. The first thing to isolate is the mic. Take it to a friend, or back to the dealer and hook it up to a system everyone know works well. Be sure to turn off any phantom power as the tube mic does not need it. Make sure the voltage on the supply is set to 230V. If the TB1 performs well on another system without hum, then its time to check yours for grounding,, but the first step is to see if the mic is at fault.

If it is, we stand behind it 100%, but the TB1 is the first thing to check, and to do that, you need to do outside of your system. This card you have does not have balanced XLR input, so you lose 6dB there, and it looks like it is set for a -10 operating level, which is also an issue as the TB1 wants +4. The spec on a web site I found say the following about the mic input: 1 x microphone - input - mini-phone mono 3.5 mm

So, this may be the issue itself... It is mono unbalanced at -10, so you have to crank up the volume so high that the system itself is probably humming.

Hey, I could be wrong, so check the mic out on another system first...

[Alexbaker443]

Thanks to everyone for the feedback. Alan, I sent you the below before I got a chance to noticed you'd written back here also:

'Alan,

Thank you for your quick reply. I ran many tests before e-mailing you, trying to eliminate the problem. I have checked that all the leads and equipment is earthed, I have tried different cables, checked all the screws and tried running the mic through four different audio setups (including one mixer). The adaptor is indeed set to 230V. In addition to the hum I'm recieving, the signal is also very low (around about -40 dB when speaking about 6" away from the mic) with no gain added. The sound that the mic does pick up is beautiful quality, and that's why I'm happy to have chosen this mic. I'm currently in contact with DV247 in ordering a replacement.
I have used many mics with my current set up, and this is the only one with these problems. I don't think it is my equipement, as the mic is probably the cheapest of the equipement in the current set-up.
Any other suggestions?
Thanks for you time,

Alex'


I'm interested by what you wrote about the DMX. It does seem that the problem may be coming from there, after reading the statistics you wrote. I'll take it to another friends and run it through his mixer, and check the results.
I'll let you know.
What soundcard would be suitable with the mic, do you mind me asking?